#include <iostream>
#include <fstream>//if chang this file to ifstream , then compiling error,I wonder this error

using namespace std;
void catfile(const string& file_name)
{
    ifstream ifs(file_name.c_str());
    string line;
    cout << "Conten of file: " << file_name << endl;
    while(getline(ifs,line))
    {
        cout << line << endl;
    }
    
}

int main(int argc, char* argv[])
{
    if( argc == 1){
        cout << "You need give me argument." << endl;
        return -1;
    }
    else{
        cout << "Hello ";
        for(int i = 1; i < argc; ++i){
            catfile(argv[i]);
        }
    }
    return 0;
}
